title: Electrochemically oriented immobilization of antibody on poly-(2-cyano-ethylpyrrole)-coated gold electrode using a cyclic voltammetry.
abstract: Using quartz crystal microbalance (QCM) as an immunosensor, this work investigates the contribution of a cyclic voltammetry (CV) on the proper immobilization of antibodies with the aim of enhancing its target recognition and binding ability. Primarily, CV in the range of -0.1 to 0.9 V was applied to form a layer of poly-(2-cyano-ethylpyrrole) (PCEPy) on gold quartz crystal electrode. Then the efficiencies of antibodies (anti-IgG, AIgG) immobilized electrochemically with CV applied in 0-0.65 V were compared to those immobilized via physical adsorption, by observing relative affinity towards AIgG-Fab and AIgG-Fc fragments. The results showed antibody-AIgG-Fab interaction could be enhanced about 4 times when CV is applied (11.2 ± 1.3 vs 41.6 ± 3.4 relative fluorescence unit). On the contrary, physisorbed antibodies showed a higher degree of affinity towards AIgG-Fc indicating inappropriate orientations of physisorbed antibodies. AIgG immobilized PCEPy-gold QC electrode was characterized further for its sensitivity towards a new target bovine albumin with both a QCM and fluorescence measurement. Such electrode exhibited a good sensitivity as well as a large linear dynamic range, from 0.4 μg/ml to 1.0 μg/ml and from 0.5 μg/ml to 10.0 μg/ml, at QCM and fluorescence measurement, respectively.
authors.affiliation: Department of Microbiology, Chungbuk National University, 410 Sungbong-Ro, Heungduk-Gu, Cheongju 361-763, South Korea.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Um
authors.forename: Mina
authors.initials: M
authors.lastname: Kim
authors.forename: Sang-Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Jiho
authors.initials: J
authors.lastname: Min
authors.forename: Hongik
authors.initials: H
authors.lastname: Kim
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Choi
authors.forename: Yang-Hoon
authors.initials: YH
authors.lastname: Kim
mesh_terms: D000906:Antibodies / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D000906:Antibodies; D011108:Polymers; D011758:Pyrroles; D006046:Gold